Correct maintenance of the apron can keep the quality of the apron in good condition. When the apron is in operation, the fibers affected by the drawing force constantly rub against the surface of the apron, and between the roller and the inner layer of the apron. After a period of use, surface roughness, grooves, damage, and fiber impurity sticking will appear, resulting in an increase in the friction factor on the surface of the apron, thus destroying normal drafting. Therefore, the apron must be maintained periodically to prevent yarn defects and breakage caused by defective apron. In addition, periodic replacement can restore the elasticity of the rubber ring and prevent early cracking caused by operating fatigue, thus extending the service life. The use conditions of apron are different, so the maintenance period is also different, which should be determined according to the requirements of spinning variety and process settings.  

  Rubber ring replacement cycle

  The replacement cycle can be combined with a small flat car or a wiper car. With the upgrading of equipment, textile mills employ fewer and fewer workers, and equipment maintenance has undergone fundamental changes. For example, the large flat car is cancelled, and even the small car flat car and partial preservation are cancelled. Only maintenance is used to complete the equipment maintenance work. Therefore, replacing the rubber ring can be done regularly by inserting it into the maintenance content. The establishment of the replacement cycle varies depending on the conditions of use, and is generally determined according to the variety and process requirements. When cotton wax, sugar or synthetic fiber grease is deposited on the surface of the rubber ring, it must be replaced. The replaced rubber ring should be cleaned with high-quality cleaning agent in a washing machine with a water temperature below 60 ℃, and rinsed with tap water. In areas with high alkali content in tap water, water with improved water quality should be used for cleaning. Otherwise, the cleaned rubber ring will easily become twisted after being put on the car.  

Replacement cycle: 3 to 6 months for spinning cotton with spun yarn and apron; 2 to 3 months for spinning chemical fiber blends; about 3 months for cotton spinning with roving apron, and 0.5 to 1 month for spinning blends; if spinning pure cotton encounters raw materials with high sugar content or dirty cotton, the apron application cycle needs to be shortened to facilitate smooth spinning.  

Rubber ring update cycle

After the rubber ring has been running for a period of time, mechanical fatigue will occur and network cracks will appear on the surface. Cracks generally occur first at the molecular interface or the interface of the vulcanized rubber mixture. The mixture has poor compatibility and the larger the particles, the more obvious the interface, and the easier it is to produce cracks. When slight cracks appear on the surface of the rubber ring, the cracks will extend quickly under the action of flexural stress; at the same time, ozone molecules invade the vulcanized rubber, causing the rubber molecular chains to slowly break, starting at the surface, and then gradually deepening, causing greater and greater damage. Therefore, the apron needs to be updated at the beginning or before mechanical fatigue occurs, otherwise short lint and flying fibers will be caught in the yarn, causing yarn defects and affecting the spinning quality. 

In recent years, apron product formulas have been greatly improved to delay mechanical fatigue of the apron. After the improvement, although no cracks were found on the surface of the apron, the surface hardness increased and the elasticity weakened. During the drafting process, the friction factor decreased, and the +35% short stubs increased significantly, which directly affected the spinning quality. Since it is difficult to find out the cause, the apron should be updated periodically. 

The determination of the apron update cycle is related to the host machine model, spinning variety and production environment. Under normal circumstances, the apron renewal cycle for pure cotton varieties is 1 year; the apron renewal cycle for chemical fiber blended varieties is approximately 9 months.